The BLOCH beamline consists of two branchlines, and is dedicated to high resolution photoelectron spectroscopy, encompassing angle-resolved (ARPES), spin resolved (spin-ARPES) and core-level spectroscopy. Located on the 1.5 GeV storage ring, it employs an quasi-periodic elliptically polarising undulator (q-epu) as a photon source. Equipped with gas filters, solid state filters and q-epu for minimising higher order light contamination, the BLOCH beamline offers photon energies with controllable polarization spanning UV to soft X-ray (10-1000eV). The beamline is optimised for lower energies and is capable of 1meV resolution upto 100 eV. 

Branchline 1 has an end station dedicated to high-performance ARPES experiments, ideal for mapping energy dispersions and Fermi surfaces. The end station consists of six ultra high vacuum chambers connected by a radial-distribution chamber. Besides the main analysis chamber there are two flexible and well equipped preparation chambers (dedicated to high- and low-vapour pressure evaporation sources), a scanning tunnelling microscope, a sample storage chamber and a fast-entry load-lock. The analysis chamber is equipped with a fully motorized six-axis manipulator capable of cooling samples to below 20K, paired with a high performance deflector based DA30 hemispherical analyser from SCIENTA-OMICRON. Deflection mode measurements enable Fermi surface mapping without needing to rotate the sample which is advantageous for very small or inhomogeneous samples and also for maintaining a fixed polarization geometry.

Branchline 2 will be dedicated to spin-resolved ARPES measurements. Endstation is currently in the design phase.

Research applications at this beamline cover a range of important topics in material science, including new materials, various class oftopological materials, surface alloys, correlated systems, organic molecular layers, magnetic semiconductors, superconductors etc.

 

 

 

 

 

 

Endstations or Setup

ARPES endstation

Description
The ARPES endstation.
It consists of the following parts:
- Analysis chamber
- Main preparation chamber
- Secondary preparation chamber
- Transfer chamber
- Analyzer (spectrometer)
- STM
Spectrometer
ScientaOmicron DA30-L
Base Pressure
10 * 10-11 [mbar]
Endstation Operative
Yes

Sample

Sample Type
Other: Solid-state samples

Manipulator or Sample stage

Description
Analysis chamber:
Samples are mounted on the 6-axis CARVING LHe manipulator for the ARPES experiments..
Description
Main preparation chamber:
Samples are mounted on a 4-axis Prevac LHe open cycle manipulator.
Description
Secondary sample chamber:
Samples are mounted on a 4-axis Prevac LN2 manipulator.

Sample Environment

Description
Analysis chamber:
Dual μ-metal liner (residual magnetic field < 0.1 μT).
Direct current heating.
LHe and LN2 cooling.
Pressure (min)
10 * 10-11 [mbar]
Temperature
20 - 300 [K]
Description
Main preparation chamber:
Sputter gun.
Electron beam, resistive, and direct current heating.
LHe and LN2 cooling.
Gas dosing through leak valve.
Pressure (min)
8 * 10-11 [mbar]
Description
Secondary preparation chamber:
Sputter gun.
Electron beam and resistive heating.
LN2 cooling.
Gas dosing through leak valve.
Heavy evaporation using replaceable inner liner.
Pressure (min)
8 * 10-11 [mbar]
Description
STM:
Indirect radiative heating.
LHe or LN2 cooling.
Temperature
50 - 500 [K]
Description
Transfer chamber:
Thermally isolated 2-sample transfer carrier.
LN2-cooled sample stage.
Resistive and direct heating.
Pressure (min)
8 * 10-11 [mbar]

Spin-ARPES endstation

Description
The Spin-ARPES endstation.
Installed on the second branch of BLOCH - Under commissioning.

Sample

Sample Type
Other: Surfaces and thin films.
Detectors

Analyzer - ARPES endstation

Type
ScientaOmicron DA30-L
Description
Energy resolution: < 1.8 meV FWHM at 2 eV pass energy and 20 eV kinetic energy
Angular resolution: < 0.1 degree

Detector: 40 mm MCP/CCD

Slits: 0.2s, 0.3s, 0.5s, 0.8s, 1.5s, 2.5s with aperture
0.1s, 0.2s, 0.3s without aperture (s = straight)

Angular mode
±3.5°,±7°,±15°

Deflection mode
Θx:±15°,Θy:±12°
Θx:±7°,Θy:±7°
Θx: ± 3.5°, Θy:± 3.5°

Detection

Detected Particle
Electron
contacts
Johan Adell
Techniques
Photoelectron emission
  • Angular Resolved PES
  • Spin-resolved ARPES
Disciplines
Physics
  • Other - Physics
Address
MAX IV Laboratory
Fotongatan 2
224 84 Lund
Sweden
control/Data analysis
Control Software Type
  • TBC
Data Output Type
  • TBC
Data Output Format
  • TBC